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Mad Harold
United Kingdom
228 Posts |
 Posted - 23 Jun 2020 : 18:59:17
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First check will be cooling water inlet strainer (if fitted).Then the water filter proper.It will probably have a screw on translucent top.
Weed blockages are very common.Check that belt driving the water pump is correctly adjusted,and that there is sufficient coolant in the engine system.Check for coolant leaks (it usually smells like curry)
If all this draws a blank,check the ignition timing,too retarded will cause overheating. |
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IanM
United Kingdom
2238 Posts |
Posted - 23 Jun 2020 : 20:16:07
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When the boat towing you bursts into flames you should shout encouragement to the owner and carefully cast off any ropes that bind your boat to his...
Sluggish is air or fuel supply.
Smoking - hard to say. Have you got a temperature gauge fitted? |
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df
United Kingdom
5991 Posts |
Posted - 23 Jun 2020 : 20:19:24
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What colour is the smoke? Black and it's too rich, blue and the engines knackered (oil burning), white/grey could be steam not smoke.
What sort of cooling system does it have? Is it direct from river water or indirect with a heat exchanger cooled by river water? Have you checked raw water pump impellor for broken vanes?
NBAS--The communal colostomy bag of the boating community.
 Visit leomagill.co.uk |
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DavidAshton
United Kingdom
53 Posts |
Posted - 23 Jun 2020 : 21:00:46
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It happened so quick I didn’t know what to do, the guy was seconds away from being burnt alive, w hug at saved him is the V at the back of the boat as all the leaking fuel was going in the river and not in the boat otherwise he’d have been in big trouble. Really shook me up
It was more ‘overheating’ smoke (Steam) I guess, like a radiator on a car, my initial plan was to leave it to cool down then top up with water just to get back
Think it’s direct from river, there is a temp gauge but didn’t check it, when it was running I thought maybe old fuel working through the system as it’s the first run out so overlooked it
Had a check for weed blockages and couldnt see anything
Just to add, so it was struggling to run before matey boy sorted the spark plugs, when in neutral, when he did the plugs it was ok... for a while, then I could tell that if I put it in neutral it would stall So might be Fuel
Assumed overheating was water pump?
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Mad Harold
United Kingdom
228 Posts |
Posted - 23 Jun 2020 : 22:04:50
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Could you post a picture of your engine installation,because it could be direct or indirect canal water cooled.Direct is when canal water is pumped around the water jacket,and indirect is where the engine coolant is pumped by the engine pump through a heat exchanger and the canal water is pumped through the heat exchanger by a second Jabsco type pump.
If yours is direct raw water cooled,it should have a Jabsco type pump,and if it is using the engine pump,it will not circulate the water the distance required and cause overheating.
Difficult to say without a picture. |
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Fred
2007 Posts |
Posted - 23 Jun 2020 : 23:43:34
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Sounds to me just a failure of cooling system.
1. Check that seacock is fully open.
2. Check that inlet is not fouled (push a wire through).
3. Check that inlet strainer is not blocked with weed or muck.
4. Remove cover and check impeller in pump. They soon wear and even one damaged vane can cause problems. You'll need a new paper gasket if you replace the impeller.
5. Check pump drive belt tension.
6. Don't play with matches. 
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df
United Kingdom
5991 Posts |
Posted - 24 Jun 2020 : 07:53:58
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As it has stood you may need to prime the raw water system before it will pick up as the slightest air leak can stop it self priming, I have one pump that's bad for this despite being fully rebuilt and machined to take jabsco wear plate, to prime close the seacock and fill the weed strainer full of water, spin engine over till the level starts to drop with seacock still closed, then stop engine and re-top the strainer and put the lid back on, open seacock and try again, check exhaust to make sure water is coming out.
This assumes vetus type strainer, if clear lid you can put some plastic floating bits in the strainer so you can see the water movement when it's running (I used balls from a kids game, don't know what game but the balls have eyeballs...).
But check the impellor first as well as state of face plate and back of pump housing for bad wear grooves.
A piccie of your engine setup would help no end so we can see what type of pump/strainer/cooling system you have.
NBAS--The communal colostomy bag of the boating community.
Visit leomagill.co.uk |
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cliveshep
Thailand
1324 Posts |
Posted - 25 Jun 2020 : 02:17:34
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Just to dot the "T"s and cross the eyes lol.......Look for a fitting somewhere beside the engine bolted through the bottom of the boat and with a rubber/plastic/metal pipe connected to it and a wheel or lever on the side - that's the sea cock. The top of it should be above outside water line but you'll soon know when you undo it. If there is a bit of a whoosh turn off the lever or round wheel otherwise make sure it is full open.
On top of it will be a screwed cap - take it off and insert finger and pull out the mesh strainer inside. Without letting go of it bang it on outside of boat to allow all the bits of weed to drop back whence they came. Peer down sea-cock - on a moderately bright day enough light should enter the water to show a dull circle, if it doesn't look clear poke a long wire - coat-hangers are good - down it to clear it.
Replace the mesh strainer you didn't previously drop in the 'oggin and screw the cap back on.
Now follow hose/pipe which will go to front of engine to a round brass lump with a pulley on the front. That pulley should have a vee belt from the engine driving it, OR - and this is important - if no pulley it will be driven from the camshaft inside the front timing cover. Anyway that brass lump is the Jabsco (probably) raw water pump. It has a front cover with 5 or 6 screws. Holding a rag underneath it to catch any screws your stubby little fingers might inadvertently let go of undo the screws, put them safely in a cup or something and take off the cover plate.
Inside is the neoprene rubber impeller, first check and remember or use that natty little i-phone she made you buy and take a picture because if you fit a new impeller with the vanes folded back the wrong way you get all sorts of problems chief of which is bits of your expensive new impeller distributed throughout the cooling system and an engine overheat. The exhaust also gets incredibly noisy and if you keep it going will in short order set the exhaust hose and then the boat alight.
You might want to avoid that!
So - impeller - take it off by prising or pulling with those same stubby fingers. Now inspect the vanes carefully - are they all there for a start? If not further work in order. Check for cracks where they fold back - any signs of stress at all it is knackered - off to boatyard with it for a replacement. To be fair it's probably a bit like insurance, the car doesn't go any faster but it's just something you need to have so I suggest you swallow manfully and fit a new impeller anyway unless you are sure yours is only a few weeks old and perfect.
Now the technical bit - all that was child's play your 5 yr old or a smart wife could have done.
Look at the pump - it has the hose from the sea-cock - we'll be clever and call that the raw water inlet hose, and it has a hose coming out. It follows that if you pump up water it has to go somewhere and this is no exception - you have to ascertain exactly where that somewhere is.
Two types of engine cooling - one is direct and the other isn't - it's indirect oddly enough!
Direct cooling the outlet pipe does something crazy - it is connected to the front of the engine, and somewhere else on the engine you'll find another pipe coming out and connected to the exhaust manifold by a little spigot tube welded to the top of the elbow connected to the exhaust manifold.
Crazy huh, those injuneers got some balls! So canal/river/sea water (adventurous little "Oh my word" aren't you?) is sucked up, pumped around your engine to cool it and is then spat out into the exhaust. That is why you got that lovely little burbling outside the boat and repeated spurts of water coming out the back. So what happens is the hot gases from the engine are cooled by having the water pumped down into them. If they didn't things would get interesting down there because those gases are HOT man!
The other method of cooling is indirect, simply put the water from the pump goes into a box, often a jacket around the exhaust manifold, and comes out at the other end and is "injected" into the exhaust elbow as before. But that box is a heat exchanger and where on a car you got top and bottom hoses into and out of a radiator on this system they go into and out of the box which has a sealed tube stack in the middle around which the engine coolant is pumped by the engine water pump. Where you see those big stepped rubber ends to the box they hold the tube stack and also seal to the end of the box. Water from the river passes through that stack on it's way to the exhaust injection elbow. Engine water flows around the stack and is cooled by it. So that's the heat exchanger which has a familiar radiator cap on the top because that is where you top up the engine coolant. That should have an anti corrosion anti-freeze in it by the way.
So now you understand how it all works you can apply for a job with Vetus!
But first - earlier point - if ANY vanes are missing from that impeller they cannot pass through the tube stack of an indirect system out through the exhaust - so you need to find them by removing all the pipes of the raw water system, and crazy as it sounds that means the inlet pipe back to the sea-cock because I have known vanes to drop back down that and block it. You need to make sure those missing vanes are not going to cause trouble later, also take off the top hose connection on a direct cooled engine and check nothing inside the thermostat housing. Easier to do that on a cold engine on a mooring than adrift struggling with a hot engine miles from home.
I advise that no matter what you find, you buy two impellers, fit one, put the other in the galley drawer for emergencies.
Trust your Scents of Yuma are still with you and the forgoing essay will prove useful.
Finally living the dream!
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Edited by - cliveshep on 25 Jun 2020 02:22:33 |
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df
United Kingdom
5991 Posts |
Posted - 25 Jun 2020 : 18:08:20
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It's also worth noting that sea cocks do fail and in either position but the lever or wheel often feels like it's working perfectly, so worth poking something through with it open and also attempt in with it shut to check it's working properly.
We have been assuming weed strainer above water line with screw top, this is not always the case, often there's a brass tube attached to the sea cock usually with 2 studs and a plate on top, these are generally below the waterline so be aware when opening it, it can be quite frightening when water gushes in but it takes a good while to actually sink a boat like that, even with water coming in it's still worth a prod through but work quickly with a vax on hand.
NBAS--The communal colostomy bag of the boating community.
Visit leomagill.co.uk |
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DavidAshton
United Kingdom
53 Posts |
Posted - 28 Jun 2020 : 16:16:04
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Ok most of the info although excellent went over my head!!
But...
I opened the Sea Cock, took out the filter and it was completely blocked with weeds, mud and alsorts!!!
Cleaned it out, and the boat started nicely and ran ‘stationary’ lovely
Didn’t take it out but all seemed ok
So, in theory would this be fixed, and safe to go out for trips??? Would this problem alone cause the engine to overheat
Just worried as it really did get hot so worried about any damage I did |
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df
United Kingdom
5991 Posts |
Posted - 28 Jun 2020 : 16:45:41
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Still worth checking the impellor in the water pump, they soon burn out if run dry.
How much water comes out of the exhaust?
NBAS--The communal colostomy bag of the boating community.
Visit leomagill.co.uk |
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trevork
3949 Posts |
Posted - 28 Jun 2020 : 17:07:15
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| Simple but eminently sensible question by Dave there! I recall vividly just how obsessed with looking at the tail pipe to check the water coming out on my first Norman. Its the same today, whenever I start my engine, my first question is always "Is there water coming out and is it enough"?? |
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DavidAshton
United Kingdom
53 Posts |
Posted - 28 Jun 2020 : 17:25:56
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Looked to be plenty coming out once cleared, we tried starting the boat before cleaning it and nothing was coming out
where about's is the water pump located?
at least this is progression, I felt like scuttling the boat the other day - don't feel like that now!
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philihun
United Kingdom
283 Posts |
Posted - 28 Jun 2020 : 17:43:25
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If anybody questions the value of the above unpaid advice.
Have an engine problem and then subscribe to an american specialist who will for £5 tell you in about 15 words to take it to a mechanic. And if you don't then cancel will bill you £35 per month till you do.
I posted recently about engine overheat probs on a Mariner 25 efi on this site. My £5 answer from USA was so nonsensical i asked if i was talking to a robot. (all in txt btw).
Answer came back yes you are . Upgrade to monthly and get some live chat lol.
pr hunt |
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Fred
2007 Posts |
Posted - 28 Jun 2020 : 22:08:54
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David - this will give you fair idea of what's involved. (Ignore the ads at the start and the electric clutch bit!!)
Your Jabsco pump will be at the front of the engine.
https://www.youtube.com/watch?v=HY8hzyPnkqA |
Edited by - Fred on 28 Jun 2020 22:10:11 |
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